The present invention relates in general to medical instruments suitable for endoscopic or laproscopic applications, and capable of passing through a trocar or similar device. More specifically, the present invention relates to a novel hydraulically actuated medical instrument suitable for stapling or other desired endoscopic or laproscopic applications.
Surgical instruments, such as staplers, graspers, scissors, coagulators and the like, suitable for endoscopic or laproscopic applications in which the device is inserted through a cannula or trocar, are well known. As described in more detail below, the present invention, in its most preferred embodiment, is directed to an endoscopic stapler particularly suited for minimally invasive surgery for isolating the left atrial appendage on human hearts.
In U.S. Pat. No. 5,306,234, incorporated by reference herein, Dr. W. Dudley Johnson described a minimally invasive procedure for isolating the left atrial appendage of the human heart from the associated atrium. It is known that during atrial fibrillation blood may pool in the left atrial appendage. When blood pools in the atrial appendage, clots may form. Upon the resumption of normal beating, these clots may be ejected from the appendage and enter the blood flow to other parts of the body. If the clots enter the arteries of the brain or heart, stroke or heart attack may result.
In his patent, Dr. Johnson described a procedure for isolating the left atrial appendage without requiring open heart surgery, as was previously used. Specifically, he described entering the chest cavity between selected ribs with a minimally invasive opening or openings, while maintaining the sternum and ribs intact. While this procedure holds great promise, there remains a need for instruments suitable for conveniently and efficiently carrying out this procedure. The present invention provides such an instrument, although it also has aspects and features not limited to the particular procedure described in Dr. Johnson's patent or to stapling apparatus procedures in general.
Also, endoscopic medical instruments are often of complicated construction, especially when the instrument is articulated to allow the handle and/or end effector to pivot or rotate. Typically, a mechanical linkage extends between the handle and end effector to allow operator actuation of the end effector. When the instrument is of the type that permits articulation, the mechanical linkage must accommodate the articulation. This often results in a design that is relatively complicated, that is costly to manufacture and/or that may still experience limitations regarding the degree or direction of articulation.